The present invention is directed to the use of certain compounds which can act as modulators of viral replication and/or virus production, especially of the hepatitis C virus (HCV), in a cell based system.
It is estimated that about 3% of the world's population are infected with the Hepatitis C virus (HCV) (Wasley, et al., 2000, Semin. Liver Dis. 20, 1-16). Exposure to HCV results in an overt acute disease in a small percentage of cases, while in most instances the virus establishes a persistent infection that results in chronic hepatitis, liver cirrhosis and liver failure (Iwarson, 1994, FEMS Microbiol. Rev. 14, 201-204). In addition, epidemiological surveys indicate an important role of HCV in the pathogenesis of hepatocellular carcinoma (Kew, 1994, FEMS Microbiol. Rev. 14, 211-220, Alter, 1995. Blood 85, 1681-1695).
Investigating the effects of antiviral compounds on HCV replication is complicated by the absence of a way to reproduce infection in laboratory small animal models as well as in cultivated cells. HCV infects human and chimpanzees, but does not infect small animals such as mice and rats. Similarly, HCV does not efficiently propagate in any cultivated cells or tissues.
Lohmann et al., Science 285, 110-113, 1999 disclose a HCV cell culture system where the viral RNA self-replicates in the transfected cells efficiently, and illustrate the ability of a bicistronic HCV subgenomic replicon to replicate in a hepatoma cell line. An HCV replicon is an RNA molecule able to autonomously replicate in a cultured cell and produce detectable levels of one or more HCV proteins.
HCV replicons can thus be used to produce a cell culture replication system providing detectable levels of HCV RNA and HCV protein. In order to replicate efficiently, however, the majority of the available replicons require the presence of adaptive mutations (see for example, Lohmann et al., J Virol 77, 3007-3019, 2003).
Adaptive mutations are mutations in HCV RNA that enhance the ability of an HCV replicon to be maintained and expressed in a host cells. Examples of adaptive mutations can be found in U.S. Pat. No. 6,630,343 B1; WO2002059321 A2; WO0189364 A2; Bartenschlager et al., Antiviral Res. 60, 91-102, 2003, and references therein.
Certain phenylpiperazine and phenylpiperidine derivatives have been disclosed in the art but none are disclosed as being useful as modulators of viral replication.
Published International application WO 98/00134 (Merck & Co., Inc.) discloses the compounds of formula (A):X—Y—Z-A-B  (A)wherein X is a 5, 6 or 7 membered aromatic or nonaromatic ring, and Y is a 5 or 6 membered aromatic ring, such as:
as fibrinogen receptor antagonists.
Published International application WO 03/076422 (Janssen Pharmaceutica N.V.) discloses the sulfonyl derivatives of formula (B):
where A, L, Q, X, Y, Z, R1, R2, R3, R4, n and t are defined therein, as inhibitors of histone deacetylase.
Published International application WO 99/38849 (Meiji Seika Kaisha, Ltd.) discloses the compounds of formula (C):
where A, Q, X, Z, R4, R5, R6, R7, R8, R9, m, n, p and q are defined therein, as integrin αvβ3 antagonists.
Published International application WO 97/25323 (SmithKline Beecham Corporation) discloses the compounds of formula (D):
where A1, A2, A3, D, Q, X, Z, R1, R2 and n are defined therein, as fibrinogen receptor antagonists.
Published European application EP 277725 (A.H. Robins Company, Incorporated) discloses 4-aryl-N-[2-(dialkylamino and heterocyclicamino)alkyl]-1-piperazinecarboxamides of formula (E):
where B, Ar and Q are defined therein, as antiallergy agents.